Canada though can take pride from their spirited performance as they battled hard throughout, scoring one try of their own through DTH van der Merwe.

Canada, who were without influential captain Tyler Ardron and full-back Harry Jones for the game, began strongly as fly-half Nathan Hirayama's slick distribution put team-mates on the outside shoulder of the Irish defenders. However, Ireland were soon enjoying most of the territory.

Hirayama was the catalyst for Canada as this time he unlocked Ireland with a lovely step 40 metres out. Again though the Irish repelled them until number eight Jamie Heaslip was penalised at ruck time, allowing Canada scrum-half Gordon McRorie a shot from 52 metres which went wide.

3-0 would become 10-0 on nineteen minutes as sustained pressure led to O'Brien mauling over from a close-range line-out, this after Canada's Jamie Cudmore was shown a yellow card for hands in the ruck. One wondered whether this would open the floodgates at the Millennium Stadium.

Paul O'Connell went close only to be held up but his in-form second-row partner Henderson would not be denied as the Irish moved 17-0 in front.

Ireland were cruising at this point and their third try was not long in coming, as a nice interchange between O'Brien and Sexton saw the fly-half find a mismatch in defence and race over in the left corner. His conversion miss was the only blot on an otherwise excellent 30 minutes.

As Ireland cantered, Canada were chasing shadows as they spread the play well to allow right wing Kearney a run in for the try bonus point. The extras made it 29-0 before Van der Merwe and Canada were cruelly denied a try due to Hirayama's forward pass. That score was sorely needed.

What the near miss did offer Canada was hope, not of a titanic comeback, but of salvaging something from a game that looked to have long gone. They pressed hard for a score early in the second-half and with O'Connell having been sent to the sin-bin for offside, Canada were encouraged.

The try wouldn't come in that passage as Ireland recovered to mount their own onslaught. But like their opponent, Canada showed stout defence, forcing handling mistakes from the Irish, who had brought off Sexton, Rory Best and Mike Ross for Ian Madigan, Sean Cronin and Nathan White.

With the Irish tweaks, Canada sensed uncertainty and came back on the hour mark with good ball in the 22. Replacement scrum-half Phil Mack had lifted his troops but once again Schmidt's men kept their try-line intact, forcing a penalty at the breakdown as Madigan cleared their lines.

They would rub salt into Canadian wounds too when replacement Cronin powered over from five metres out to push Ireland way out at 36 in front.

It seemed fitting though that Canada would get something from the game and from a loose Irish pass, Van der Merwe was rewarded for all of his hard work in the game with a clean run-in down the left wing from halfway. Hirayama's extra two points turned their zero into a 36-7 deficit.

But Ireland would have the final say via a breakout score as Earls outpaced John Moonlight down the wing before setting up Rob Kearney who ran in under the posts.

Outside centre Payne was finally put through by Madigan to send Ireland over the 50-point barrier and give them the perfect start.

Man of the match: An excellent first half from Jonathan Sexton helped set Ireland on their way in Cardiff. If the Irish are to go all the way in this World Cup there is no question that Sexton has to be on his game and judging from this, he is in the mood.

Moment of the match: It's never good to see an underdog go home with 0 next to their name so when DTH van der Merwe intercepted and ran 50 metres to score, the neutrals were delighted. Few would argue that Canada didn't deserve a score.

Villain of the match: Nothing unsavoury to report in a clean game in Cardiff. Jamie Cudmore may feel a touch disappointed to have been binned early on though as Ireland subsequently turned the screw during the ten minutes the second-row was absent.